Edexcel
EDEXCEL AS CHEMISTRY QUESTION AND ANSWERS
Chemistry
Questions and Answers
, Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Unit 1
Multiple-choice questions ..............................................................................7
Structured questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Unit 2
Multiple-choice questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Structured questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Context question . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Edexcel AS Chemistry Questions and Answers © Philip Allan Updates 2
, Introduction
The new Edexcel specification for AS chemistry will be examined for the first time in 2009. This
CD contains samples of questions that might be asked in the examinations, together with the
sort of answers that an A-grade candidate should give. There is also important advice about how
examinations should be tackled and examples of common mistakes made by candidates who
achieve low grades. These questions with their answers provide a useful resource in the
important matter of examination technique, as well as helping to clarify chemical ideas.
The questions given here are not balanced in each unit in terms of type of question or level
of demand — they are not intended to typify real papers, only the sort of questions that could
be asked.
The answers are those that examiners would expect from a grade-A candidate. They are not
‘model answers’ to be regurgitated without understanding. There are also examples of common
errors that candidates make and which lead them away from the top grade.
In answers that require more extended writing, it is usually the ideas that count rather than
the form of words used. The principle is that correct and relevant chemistry scores.
Below you will find important advice on how to cope with answer papers that are marked
online and some information on marking exams and how this differs from the marking of
homework.
The new specification
There are some significant differences in question style between previous examinations and the
new ones. You should bear these differences in mind if you have to work through past papers
based on the previous specification.
Multiple-choice questions
Multiple-choice questions have been re-introduced by Edexcel for first examination in 2009.
These questions need to be read carefully; it is important not to jump to a conclusion about the
answer too quickly. You need to be aware that one of the options may be a ‘distracter’. For
example, in a question having a numerical answer of −600 kJ mol−1, a likely distracter would be
+600 kJ mol−1.
Some questions require you to think on paper — there is no demand that the working for
multiple-choice questions be carried out in your head. Space is provided on the question paper
for rough working. It is not marked, so do not write anything that matters in this space because
the examiner will not see it.
Multiple-choice answers are machine-marked. For each question there are four suggested
answers, A, B, C and D. You select the best answer by putting a cross in the box beside the letter
of your choice. If you change your mind, you should put a horizontal line through the box and
then indicate your alternative choice. Selecting more than one option does not earn any marks.
The Unit 1 and 2 examinations each have 20 multiple-choice questions, and these should
take you no more than 20 minutes. Examination papers are often written on the basis of approxi-
mately 1 mark a minute.
Contemporary contexts
Chemistry questions often involve contexts, i.e. a particular area of chemistry is linked to an
industrial process or a feature of everyday life. A context question may ask you to read a passage
and then examine the underlying chemistry. It is not a simple comprehension exercise. The
chemistry behind the context must be known, including any equations. It is in your answers to
such questions that your quality of written communication will be assessed.
Context questions appear in Unit 2 at AS and Unit 4 at A2.
Edexcel AS Chemistry Questions and Answers © Philip Allan Updates 3
EDEXCEL AS CHEMISTRY QUESTION AND ANSWERS
Chemistry
Questions and Answers
, Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Unit 1
Multiple-choice questions ..............................................................................7
Structured questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Unit 2
Multiple-choice questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Structured questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Context question . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Edexcel AS Chemistry Questions and Answers © Philip Allan Updates 2
, Introduction
The new Edexcel specification for AS chemistry will be examined for the first time in 2009. This
CD contains samples of questions that might be asked in the examinations, together with the
sort of answers that an A-grade candidate should give. There is also important advice about how
examinations should be tackled and examples of common mistakes made by candidates who
achieve low grades. These questions with their answers provide a useful resource in the
important matter of examination technique, as well as helping to clarify chemical ideas.
The questions given here are not balanced in each unit in terms of type of question or level
of demand — they are not intended to typify real papers, only the sort of questions that could
be asked.
The answers are those that examiners would expect from a grade-A candidate. They are not
‘model answers’ to be regurgitated without understanding. There are also examples of common
errors that candidates make and which lead them away from the top grade.
In answers that require more extended writing, it is usually the ideas that count rather than
the form of words used. The principle is that correct and relevant chemistry scores.
Below you will find important advice on how to cope with answer papers that are marked
online and some information on marking exams and how this differs from the marking of
homework.
The new specification
There are some significant differences in question style between previous examinations and the
new ones. You should bear these differences in mind if you have to work through past papers
based on the previous specification.
Multiple-choice questions
Multiple-choice questions have been re-introduced by Edexcel for first examination in 2009.
These questions need to be read carefully; it is important not to jump to a conclusion about the
answer too quickly. You need to be aware that one of the options may be a ‘distracter’. For
example, in a question having a numerical answer of −600 kJ mol−1, a likely distracter would be
+600 kJ mol−1.
Some questions require you to think on paper — there is no demand that the working for
multiple-choice questions be carried out in your head. Space is provided on the question paper
for rough working. It is not marked, so do not write anything that matters in this space because
the examiner will not see it.
Multiple-choice answers are machine-marked. For each question there are four suggested
answers, A, B, C and D. You select the best answer by putting a cross in the box beside the letter
of your choice. If you change your mind, you should put a horizontal line through the box and
then indicate your alternative choice. Selecting more than one option does not earn any marks.
The Unit 1 and 2 examinations each have 20 multiple-choice questions, and these should
take you no more than 20 minutes. Examination papers are often written on the basis of approxi-
mately 1 mark a minute.
Contemporary contexts
Chemistry questions often involve contexts, i.e. a particular area of chemistry is linked to an
industrial process or a feature of everyday life. A context question may ask you to read a passage
and then examine the underlying chemistry. It is not a simple comprehension exercise. The
chemistry behind the context must be known, including any equations. It is in your answers to
such questions that your quality of written communication will be assessed.
Context questions appear in Unit 2 at AS and Unit 4 at A2.
Edexcel AS Chemistry Questions and Answers © Philip Allan Updates 3